From 3ff41f2b43a89d4f8365a1002647795c983735f6 Mon Sep 17 00:00:00 2001
From: mikiher <mikiher@gmail.com>
Date: Sat, 25 Nov 2023 23:49:56 +0200
Subject: [PATCH] Cache HTTP headers and status

---
 server/managers/ApiCacheManager.js           | 11 ++++---
 test/server/managers/ApiCacheManager.test.js | 30 ++++++++++++++------
 2 files changed, 28 insertions(+), 13 deletions(-)

diff --git a/server/managers/ApiCacheManager.js b/server/managers/ApiCacheManager.js
index b311af53..c6579ab3 100644
--- a/server/managers/ApiCacheManager.js
+++ b/server/managers/ApiCacheManager.js
@@ -4,7 +4,7 @@ const Database = require('../Database')
 
 class ApiCacheManager {
 
-  defaultCacheOptions = { max: 1000, maxSize: 10 * 1000 * 1000, sizeCalculation: item => item.length }
+  defaultCacheOptions = { max: 1000, maxSize: 10 * 1000 * 1000, sizeCalculation: item => (item.body.length + JSON.stringify(item.headers).length) }
   defaultTtlOptions = { ttl: 30 * 60 * 1000 }
 
   constructor(cache = new LRUCache(this.defaultCacheOptions), ttlOptions = this.defaultTtlOptions) {
@@ -30,17 +30,20 @@ class ApiCacheManager {
       const cached = this.cache.get(stringifiedKey)
       if (cached) {
         Logger.debug(`[ApiCacheManager] Cache hit: ${stringifiedKey}`)
-        res.send(cached)
+        res.set(cached.headers)
+        res.status(cached.statusCode)
+        res.send(cached.body)
         return
       }
       res.originalSend = res.send
       res.send = (body) => {
         Logger.debug(`[ApiCacheManager] Cache miss: ${stringifiedKey}`)
+        const cached = { body, headers: res.getHeaders(), statusCode: res.statusCode }
         if (key.url.search(/^\/libraries\/.*?\/personalized/) !== -1) {
           Logger.debug(`[ApiCacheManager] Caching with ${this.ttlOptions.ttl} ms TTL`)
-          this.cache.set(stringifiedKey, body, this.ttlOptions)
+          this.cache.set(stringifiedKey, cached, this.ttlOptions)
         } else {
-          this.cache.set(stringifiedKey, body)
+          this.cache.set(stringifiedKey, cached)
         }
         res.originalSend(body)
       }
diff --git a/test/server/managers/ApiCacheManager.test.js b/test/server/managers/ApiCacheManager.test.js
index 2cfc0dfc..dc1ee1ed 100644
--- a/test/server/managers/ApiCacheManager.test.js
+++ b/test/server/managers/ApiCacheManager.test.js
@@ -13,14 +13,14 @@ describe('ApiCacheManager', () => {
   beforeEach(() => {
     cache = { get: sinon.stub(), set: sinon.spy() } 
     req = { user: { username: 'testUser' }, url: '/test-url' }
-    res = { send: sinon.spy() }
+    res = { send: sinon.spy(), getHeaders: sinon.stub(), statusCode: 200, status: sinon.spy(), set: sinon.spy() }
     next = sinon.spy()
   })
 
   describe('middleware', () => {
     it('should send cached data if available', () => {
       // Arrange
-      const cachedData = { data: 'cached data' }
+      const cachedData = { body: 'cached data', headers: { 'content-type': 'application/json' }, statusCode: 200 }
       cache.get.returns(cachedData)
       const key = JSON.stringify({ user: req.user.username, url: req.url })
       manager = new ApiCacheManager(cache)
@@ -31,8 +31,12 @@ describe('ApiCacheManager', () => {
       // Assert
       expect(cache.get.calledOnce).to.be.true
       expect(cache.get.calledWith(key)).to.be.true
+      expect(res.set.calledOnce).to.be.true
+      expect(res.set.calledWith(cachedData.headers)).to.be.true
+      expect(res.status.calledOnce).to.be.true
+      expect(res.status.calledWith(cachedData.statusCode)).to.be.true
       expect(res.send.calledOnce).to.be.true
-      expect(res.send.calledWith(cachedData)).to.be.true
+      expect(res.send.calledWith(cachedData.body)).to.be.true
       expect(res.originalSend).to.be.undefined
       expect(next.called).to.be.false
       expect(cache.set.called).to.be.false
@@ -41,13 +45,17 @@ describe('ApiCacheManager', () => {
     it('should cache and send response if data is not cached', () => {
       // Arrange
       cache.get.returns(null)
-      const responseData = { data: 'response data' }
+      const headers = { 'content-type': 'application/json' }
+      res.getHeaders.returns(headers)
+      const body = 'response data'
+      const statusCode = 200
+      const responseData = { body, headers, statusCode }
       const key = JSON.stringify({ user: req.user.username, url: req.url })
       manager = new ApiCacheManager(cache)
 
       // Act
       manager.middleware(req, res, next)
-      res.send(responseData)
+      res.send(body)
 
       // Assert
       expect(cache.get.calledOnce).to.be.true
@@ -56,13 +64,17 @@ describe('ApiCacheManager', () => {
       expect(cache.set.calledOnce).to.be.true
       expect(cache.set.calledWith(key, responseData)).to.be.true
       expect(res.originalSend.calledOnce).to.be.true
-      expect(res.originalSend.calledWith(responseData)).to.be.true
+      expect(res.originalSend.calledWith(body)).to.be.true
     })
 
     it('should cache personalized response with 30 minutes TTL', () => {
       // Arrange
       cache.get.returns(null)
-      const responseData = { data: 'personalized data' }
+      const headers = { 'content-type': 'application/json' }
+      res.getHeaders.returns(headers)
+      const body = 'personalized data'
+      const statusCode = 200
+      const responseData = { body, headers, statusCode }
       req.url = '/libraries/id/personalized'
       const key = JSON.stringify({ user: req.user.username, url: req.url })
       const ttlOptions = { ttl: 30 * 60 * 1000 }
@@ -70,7 +82,7 @@ describe('ApiCacheManager', () => {
 
       // Act
       manager.middleware(req, res, next)
-      res.send(responseData)
+      res.send(body)
 
       // Assert
       expect(cache.get.calledOnce).to.be.true
@@ -79,7 +91,7 @@ describe('ApiCacheManager', () => {
       expect(cache.set.calledOnce).to.be.true
       expect(cache.set.calledWith(key, responseData, ttlOptions)).to.be.true
       expect(res.originalSend.calledOnce).to.be.true
-      expect(res.originalSend.calledWith(responseData)).to.be.true
+      expect(res.originalSend.calledWith(body)).to.be.true
     })
   })
 })
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